Perhaps the SVG viewer you are using displays SVG files smaller than desired. You might want to try Inkscape, a free application to view and edit SVG files.

drawing is bright and in black and white)

Depending on your SVG viewer, very thin black lines may be displayed as light gray lines. This effect is part of a rendering technique that is called anti-aliasing.The output should not be black/white but resemble the same colors that are used in the input. Perhaps you can attach a file for testing or send it to us via e-mail?